How to determine if a .NET Framework hotfix is ​​installed

Question

According to the Microsoft Download Page for .NET Framework 3.5 SP1 , I must install KB959209 and KB967190 immediately after installing the .NET Framework package:

IMPORTANT: after installing the .NET Framework 3.5 Service Pack 1 (either the bootloader or the complete package), you must immediately install update KB959209 to solve a number of known application compatibility issues. Additionally, on Windows Vista x64 and Windows Server 2008 x64, install update KB967190 to resolve the file association problem for XPS documents.

I am handling the installation of the .NET Framework in my installer ( Inno Setup ). So, how to determine if these two fixes are installed, so I can decide to download and install them? I do not want to bother the user with unnecessary steps, since an automatic and passive solution is preferred.

Answer 1

I had a similar problem in which I needed to determine if the installed KB was installed during the installation. My solution was to create a custom EXE that uses the DTF - Deployment Tools Foundation to verify KB, and download and install it in passive mode if it is not installed. You can then call this custom EXE from the installation process, and it can handle the details of the detection of the corresponding patch. The discussion can be found at:

Detecting and fixing Windows QFE / patch during installation